Avalanche Forecast
Issued: Mar 22nd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Persistent Slabs and Deep Persistent Slabs.
TT,
Avalanche Canada
Spring like conditions persist into Thursday afternoon, start early and finish early as solar warming is having the strongest effect typically by mid-afternoon.
The sun is heating up cornices, cliffs and steep rocky features triggering wet loose avalanches and deeper slab instabilities.
Ice climbers, be cautious of narrow gullies that act as terrain traps, as even small slides can have significant consequences.
Summary
Confidence
Avalanche Summary
Several wet loose avalanches observed in the last week occurring mid to late afternoon at all elevations southerly aspects with many stepping down to the basal weakness or triggering persistent and deep persistent slab avalanches. Large to very large deep persistent slabs have been observed throughout the region, generally triggered by a small loose wet slide, or a cornice fall.
Don't forget to post avalanche observations to the MIN.
Snowpack Summary
Sun crust on solar aspects at all elevations breaking down by early to mid afternoon. Approximately 20-30cm down is a buried sun crust at low elevations on steep southerly slopes and a surface facet layer in sheltered terrain. The mid-pack is 40 to 80cm of supportive facetted snow. Near the ground it is generally weak with large facets and depth hoar.
Weather Summary
On Thursday, expect sun with cloudy periods and freezing levels at 1600 m with light southwest winds. Late Thursday, the ridge of high pressure will give way to a more active pattern bringing 7 cm of snow, light southwesterly winds and freezing levels to 1500 m by the end of Friday.Saturday, expect scattered flurries with up to 5 cm accumulation and winds switching to northwesterly, freezing levels at 1500 m.
Detailed weather forecasts from Avalanche Canada: https://www.avalanche.ca/weather/forecast
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Be alert to conditions that change with elevation and sun exposure.
- Avoid exposure to steep sun exposed slopes.
Problems
Loose Wet
Loose wet snow avalanche activity is expected to slow down into the weekend as a new front is approaching with clouds, precipitation, and cooling temperatures. These types of avalanches can be what initiate larger slab avalanches.
Aspects: South East, South, South West, West.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Persistent Slabs
The 20cm of surface snow from March 13th has been periodically blown around, redistributed, settled, and has combined with the larger snowpack structure for the most part. There is a cornucopia of interfaces throughout the snowpack depending on aspect, elevation, and local terrain influences. There have been a few avalanches this past week which appeared to have stepped down to multiple layers. Sun will increase potential reactivity.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Persistent slab avalanches have stepped down to the deep persistent slab since the last storm meaning large triggers can influence this basal weakness.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 23rd, 2023 4:00PM
